4 Damage fetchable to a lodestone seems like enough to justify playing this as a 1 of in the side for proper lists, charge counters are just a bonus at that point.
Sadly though, does not take out forgemaster, revoker naming it, wurmcoil, steel hellkite, or some number of other shop targets. So it may just be too narrow period.
Forgemaser evading this is definitely a big blow, but in lists that are playing 4 Trinket Mage, assuredly they are playing at least 1 Pithing Needle as well, and probably more in the sideboard, so having the option of fetching Pithing Needle (for Forgemaster) and Gremlin Mine (for Lodestone and Metalworker) gives you the utmost flexibliity for the Shop matchup.
I'd play 1 Pithing Needle maindeck (in the 4 Trinket Mage list), 1-2 Gremlin Mine in the sideboard, and say, 2-3 more Pithing Needle in the sideboard. Postboard vs. shops you could then have 3-4 Pithing Needles, 1-2 Gremlin Mines, and whatever other artifact hate you have.